Position comparator



Aug. 3, 1937. J. c. KARNES POSITION COMPARATOR Filed Nov. 9, 1934 Moral? Inventor James E Karma-5 Attmrne Patented Aug. 3, 1937 UNi'i'ED STATES PATENT OFFICE 2 Claims.

(Granted under the act of March 3, 1883, as amended April 80, 1928; 370 0. G. 757) The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to a position comparator.

In pointing control systems for ordnance, searchlights, sound locators and similarly mounted members it is customary to ascertain and compute the necessary pointing data at a remote station and transmit it to the gun which is moved until a rotatably mounted pointer controlled by the gun is matched or compared with a rotatably mounted pointer controlled from the remote data station. The application of such pointer systems to the gun has resulted in a cumbersome arrangement which interferes with other equipment and with the operating crew.

The purpose of this invention is to provide a position comparator whose elements may be conveniently and compactly associated with the training mechanism of the gun. A further ob ject is to provide reference marks on a pair of parallel slides whereby under conditions of darkness registration of the marks may be determined by the sense of touch.

To these and other ends, the invention consists in the construction, arrangement and combination of elements described hereinafter and pointed out in the claims forming a part of this specification.

A practical embodiment of the invention is illustrated in the accompanying drawing, where- Fig. 1 is a view in left side elevation of a gun showing the improved comparator in association with the elevating mechanism.

Fig. 2 is a view in rear elevation.

Fig. 3 is a similar view in right side elevation of the gun showing a comparator in association with the traversing mechanism.

Referring to the drawing by characters of reference there is shown a mount comprising a base 5, a pedestal E3 rotatably carried by the base on a vertical pivot l, and a cradle 8 rotatably carried by the pedestal on horizontal trunnions 9-9. A gun H or other device is carried by the cradle.

The mount is provided with conventional training mechanisms for moving the gun. in azimuth and in elevation. Briefly, the base carries a fixed ring gear H which is engaged by a pinion E2 on a shaft l3 that is mounted on the pedestal E. A worm wheel E4 on the shaft is driven by a worm I5 on a shaft [6 to which is fixed the traversing handwheel II. The cradle 8 has the usual arc l8 which is engaged by a pinion I9 on a shaft 20 carrying an elevating handwheel 2|.

A rack 22 provided with a reference mark 23 and slidably mounted in a guide 24 on the pedestal is driven by a pinion 25 on the shaft 13 and its displacement represents the motion of the traversing mechanism or the position of the gun in azimuth. Similarly a rack 26 provided with a reference mark 21 and mounted in a guide 28 on the opposite side of the pedestal is driven by the elevating mechanism, specifically by a gear 29 associated with one of the trunnions 9, and its displacement represents the motion of the elevating mechanism or the position of the gun in elevation.

A rack 30 having a reference mark 3| is mounted alongside the rack 22 and a rack 32 having a reference mark 33 is similarly mounted with relation to the rack 26. The racks 30 and 32 are displaced to indicate, with or without corrections, the position of an instrument or in struments at a remote station, by means of selfsynchronous electrical systems for transmitting angular motion. The receiving motors 34 and 35 of the systems are positioned within the pedestal 6 and carry pinions 36 and 31 respectively meshing with the racks 30 and 32.

In operation, when the racks 30 and 32 are displaced by the motors, the handwheels I! and 2| are actuated by the gun crew a sufficient amount to maintain the reference marks on the racks 22 and 26 in register with the reference marks on the racks 30 and 32. Under conditions of darkness the operator at each handwheel may determine registration of the marks by placing a finger at the ends of the racks to feel if they are flush. When the reference marks are in register the gun will have been positioned in accordance with the position of the instrument at the remote station.

I claim.

1. A pedestal mounted for movement in azimuth, means for traversing the pedestal, a pointing member trunnioned in the pedestal, means for elevating the pointing member, a pair of first indicators carried on the outside of the pedestal and displaceable to respectively represent the position of the pointing member in azimuth and elevation, a pair of means housed within the pedestal for reproducing azimuth and elevation data, and a pair of second indicators arranged on the outside of the pedestal for comparison with the first indicators and respectively actuated by the reproducing means.

2. In a position comparator, a rotatable memher, a slide, means whereby the rotatable mem ber controls displacement of the slide, a second slide arranged adjacent to and comparable with the preceding slide, and a rotatable reproducing member controlling displacement of the seci cud slide.

JAMES C. KARNES. 

